Well, this problem is best solved by setting up a system of two linear equations.
A linear equation can be defined
y=mx+b
where
b=initial value (when x=0), and
m=rate of increase or decrease.
In the given example, the x-axis represents hour, and the y-axis, number of cells.
Chemical #1
initial value = b = 12000 cells
rate = m = -4000 / hr
The equation is therefore
y1=-4000x+12000......................(1)
Similarly, for chemical #2
initial value = b = 6000 cells
rate = m = -3000 / hr
The equation is therefore
y2=-3000x+6000 .......................(2)
The time the two will have an equal sized colony would represent the solution of the system of equations (1) and (2), i.e. when y1=y2
which means
-4000x+12000 = -3000x+6000
transpose and solve for x
4000x-3000x = 12000-6000
1000x=6000
x=6 hours.
At 6 hours from the start,
y=-4000x+12000 = -4000*6+12000 = -24000+12000 = -12000 cells
So the solution is x=6, y=-12000, or (6,-12000)
Physical interpretation
Since cells cannot have a negative number, the two are actually equal before six hours, when they are both zero.
Case 1: y=0 when x=3
Case 2: y=0 when x=2
Therefore, after three hours, both trials will have zero cells.
You have to judge whether to give the mathematical solution (x=6,y=-12000) or the physical interpretation (x=3, y=0) as the answer.
For this questions you need to memorize formula of triangle area. for question 5, just substitute the value into the formula. for Q6 you need to use pythagorean theorem formula to find the lenght of each triangle that i already seperated
Answer:
212 is the perimeter
Step-by-step explanation:
Answer:
b=1/2-9/4c
Step-by-step explanation:
first get B on one side
8b+18c=4
-18c -18c
8b=4-18c
divide both sides by 8
8b=4-18c
/8 /8 /8
b=1/2-9/4c
Answer: Discount Price/Amount = $154.56
Step-by-step explanation:
STEP 1
A Discount Is used when a seller gives a reduction in the price of its good or services. .
Given that sale of car = $1,287.99
Discount = 12%
Discount Price = 12 % x $1,287.99=$154.56
such that The Final price to purchase the car =$1,287.99 - $154.56 =$1,133.43